Naturalists know that the "killer instinct" is common in nature, characterizing predators from dragonflies to lions and tigers. Many humans also possess this trait, which may have negative connotations in some cases (serial killers, for example).
But the term might also be applied to athletic competitors, especially those who engage in individual sports such as golf, track, swimming and tennis. In such cases, the athlete demonstrates exceptional skill, self-confidence, perseverance and the fortitude to "finish the task." Many become perennial winners while others clearly lose their killer instinct during periods of their career.
Avid sports fans tend to admire these traits in athletes. While some root for underdogs nevertheless, we naturalists, students of survival, are inclined to favor those with the killer instinct.
